Means for damping vibrations, for example self-generated oscillations in boring bars and similar

Abstract

A damping device is constituted by a substantially cylindrical damper body (1) with an axial through bore (6), where the bore (6) accomodates a central pipe (3) which e.g. can lead a cooling liquid. The central pipe (3) is connected rigidly to or into the machine element to be damped, preferably in a cylindrical and axial cavity in a boring bar (9). Ring-shaped, elastic spring elements (2) placed in the ends of the damper body (1) and between the central pipe (3) and the damper body (1), as well as damping oil (4) in the clearance between the central pipe (3) and the damper body (1) transform motion energy into heat and provide the damping action. The stiffness of the spring elements (2) can optionally be adjusted.

I claim: 
     
       1. A damping device for objects which can be exposed to undesired vibrations, comprising: a substantially cylindrically shaped damper body, said damper body having a pair of ends having cutouts formed therein and an axial through bore;   a cylindrical, central support extending axially through said axial through bore and rigidly connected to an object to be damped;   resilient spring elements placed in said cutouts in the ends of said damper body for connecting said damper body to said central support; and   washers located axially outside of said spring elements and rigidly connected to said central support, said central support having an outer diameter defining a small clearance between said central support and a surface of said axial through bore for accommodating damping oil.   
     
     
       2. Damping device in accordance with claim 1, wherein said resilient spring elements are ring-shaped and lie in ring-shaped cutouts in said damper body immediately adjacent to said axial through bore. 
     
     
       3. Damping device in accordance with claim 1, wherein at least one of said washers is equipped with adjustable means for limiting expansion of one of the spring elements, thereby permitting adjustment of the natural frequency of said damper body. 
     
     
       4. Damping device in accordance with claim 3, wherein at least one of said washers is a two-part washer, an outer part of said two-part washer being rigidly connectable onto said central support and comprising a countersunk adjusting screw adapted, when turned, to offset an inner part of said at least one of said washers axially along said central support to obtain preload stiffness adjustment of a corresponding spring element. 
     
     
       5. Damping device in accordance with claim 1, wherein the spring elements are gas-filled rights of at least one of rubber and plastic materials. 
     
     
       6. Damping device in accordance with claim 5, wherein at least one of said spring elements is equipped with a nipple for adjusting gas pressure, and thereby the natural frequency of said damper body. 
     
     
       7. Damping device in accordance with claim 1, wherein the cylindrical, central support is hollow and forms a pipe for conducting fluid therethrough.